    New chain ID            Original chain ID

6x6s-pdb-bundle1.pdb:
           A                        AA
           B                        AB
           C                        AC
           D                        AD
           E                        AE
           F                        AM
           G                        AT
           H                        AU
           I                        AX
           J                        AY
           K                        Am
           L                        At
           M                        BA
           N                        BB
           O                        BC
           P                        BD
           Q                        BE
           R                        BM
           S                        BT
           T                        BU
           U                        BX
           V                        BY
           W                        Bm
           X                        Bt
           Y                        CA
           Z                        CB
           a                        CC
           b                        CD
           c                        CE
           d                        CM
           e                        CT
           f                        CU
           g                        CX
           h                        CY
           i                        Cm
           j                        Ct
           k                        DA
           l                        DB
           m                        DC
           n                        DD
           o                        DE
           p                        DM
           q                        DT
           r                        DU
           s                        DX
           t                        DY
           u                        Dm
           v                        Dt
           w                        EA
           x                        EB
           y                        EC
           z                        ED
           0                        EE
           1                        EM
           2                        ET
           3                        EU
           4                        EX
           5                        EY
           6                        Em
           7                        Et
           8                        FA
           9                        FB

6x6s-pdb-bundle2.pdb:
           A                        FC
           B                        FD
           C                        FE
           D                        FM
           E                        FT
           F                        FU
           G                        FX
           H                        FY
           I                        Fm
           J                        Ft
           K                        GA
           L                        GB
           M                        GC
           N                        GD
           O                        GE
           P                        GM
           Q                        GT
           R                        GU
           S                        GX
           T                        GY
           U                        Gm
           V                        Gt
           W                        HA
           X                        HB
           Y                        HC
           Z                        HD
           a                        HE
           b                        HM
           c                        HT
           d                        HU
           e                        HX
           f                        HY
           g                        Hm
           h                        Ht
           i                        IA
           j                        IB
           k                        IC
           l                        ID
           m                        IE
           n                        IM
           o                        IT
           p                        IU
           q                        IX
           r                        IY
           s                        Im
           t                        It
           u                        JA
           v                        JB
           w                        JC
           x                        JD
           y                        JE
           z                        JM
           0                        JT
           1                        JU
           2                        JX
           3                        JY
           4                        Jm
           5                        Jt
           6                        KA
           7                        KB
           8                        KC
           9                        KD

6x6s-pdb-bundle3.pdb:
           A                        KE
           B                        KM
           C                        KT
           D                        KU
           E                        KX
           F                        KY
           G                        Km
           H                        Kt
           I                        LA
           J                        LB
           K                        LC
           L                        LD
           M                        LE
           N                        LM
           O                        LT
           P                        LU
           Q                        LX
           R                        LY
           S                        Lm
           T                        Lt
           U                        MA
           V                        MB
           W                        MC
           X                        MD
           Y                        ME
           Z                        MM
           a                        MT
           b                        MU
           c                        MX
           d                        MY
           e                        Mm
           f                        Mt
           g                        NA
           h                        NB
           i                        NC
           j                        ND
           k                        NE
           l                        NM
           m                        NT
           n                        NU
           o                        NX
           p                        NY
           q                        Nm
           r                        Nt
